It has been suggested that human specialised capacity for commitment might have been shaped by natural selection [1]}, [2]}, [3]}. Arranging a commitment from all parties involved prior to an interaction can increase the chance of reaching mutual cooperation [4]}, [5]}, [6]}, [7]}, enabling individuals to clarify preferences or intentions from their partners before committing to a potentially costly course of actions [5]}, [9]}, [10]}, [11]}.
Theoretical models of commitments have shown that this is indeed the case in social dilemma settings [12]}, [9]}, [14]}, [15]}, [16]}, [7]}. Corresponding models, however, assume commitments are regimented, wherein compensation can always be enforced from those who dishonour an adopted commitment.
